[steveklabnik]

  > I'm not going to develop while connected to the internet.

You don't have to. If you do use crates from crates.io, then you need to be connected the first time, to get everything. Not after that.

   > ... and is this even possible?

Running your own registry with your own universe of crates is very possible. Mirroring the external world inside that one is not that easy.

  > I couldn't even find the crate. ... that isn't suitable.

Well, multi-bit fields are made up of one-bit fields... if you're looking for GDT, LDT, IDT stuff, the crate referenced in the article already has all of that defined for you. If you want to define it yourself, well, I did it with a struct and a method that handles the bit shifting.

  > I have to wonder how well it performs.

Well, Rust is itself implemented in Rust, the standard library is all in Rust, so.

Also, finally, you don't have to use crates.io to use Cargo. You can just specify crates that are on your local filesystem, or a git repository hosted anywhere.